Method and apparatus for portable refrigeration cycle



c. P. PIKEY METHOD AND APPARATUS FOR PORTABLE REFRIGERATION CYCLE Filed oct. 5. 1955 4 Sheets-Sheet 1 BY my@ April 28, 1959 c. P. PIKEY 2,383,835

METHOD AND APPARATUS FOR PORTABL REFRIGERATION CYCLE Filed Oct. 5, 1955 4 Sheets-Sheet 2 Garne/ius P. Pi/rey INVENroR.

C. P. PIKEY April 28, 1959 METHOD AND APPARATUS FOR PORTABLEYREF'RIGERATION CYCLE 4` Sheets-Sheet 5 Filed 0G13. 5, 1955 m, R m Wm m mm. .Pw s .m wn @d w W @QM @Ov QQ.

C. P. PIKEY METHOD AND APPARATUS FOR PORTABLE REFRIGERATION CYCLEl Filed Oct. 5, 1955 4 sheets-sheet 4 kE 04% .Hw 622 .1 H P w W w W 6 n @w 2 r 2 w w W m 2 2 3 2 M 3 10W m T 0 8u. M 3 fw 4 a Mi@ 3 United States Patent O METHOD .AND APPARATUS FOR PORTABLE REFRIGERATION CYCLE Cornelius P. Pikey,-Sanbom, .N .':Daln Application october 5,19's`5,serial No. v533,615

7 Claims; (CL 6244-161).

'Ihis invention relatesl generallytto .refrigeration systems and iis more `particularly concerned witha ynovel :reinigen-- tion system usable in portablefrefrigerators'whichincludes a pair -.of refrigeration ycompressors connected 1n .series to a refrigeration coilv and providing.. a closedrefrigeration system which includes dual reversible `refrigeration cycles.

A further object ofthe invention in .conformance with that set forth above ris to provide in a lrefrigeration system ofthe character set forth a novel refrigeration.-compres. sor which serves .as an -eXpanSiOnchamber .andi refrigeration compressor .in ithe .dual reversible refrigeration cycles.

Another object of the invention in conformance with that yset vforth above :is to provide in a'refrigerationisystern'l I of the character set forth means for ycontrolling `the tern-` perature'to be `niaintained'by. the dual .reversible refrigeration cycles.'

And yet anotherobject of the invention in conformance I withthat .set forth above is to provide ina refrigeration system of the characterset. forth means-.for automatically` reversing the dual-.reversible refrigeration :cycles to pro-x videcontinuous operation .of .the refrigeration system;v

These together vwith otherfobjects. and advantages' which will become subsequently apparent reside in thedetails of construction and operation .as more'fully hereinafter described `and claimed, reference being had to .the raccom-Y panying drawings forming a part hereof, wherein like numerals refer to like. parts throughout, .andiin which:

Figure l is a longitudinal sectional.viewnshowing di#V agrammatically the. novel refrigeration systemas -incor porated in a portable. refrigerator;

Figure 2 isanxenlarged fragmentary .sectional view of l.

the-metering and pressurevalve structure .of vthe com-xl pressors. of Figure V1;

Figure-3 is a sectionalyiew.1 taken. substantially. on line.

Figure 4 is a longitudinal :sectional-view similar.ztofFig-.

ure xl showing. diagrammatically va .refrigeration :sy-stem'.

affording. constant control temperature-:and continuous operation of the .novel refrigeration system;. i

Figure 5 is an enlarged longitudinal',sectional.` view of an automatic switch-over controlyalveofFigure 4;

Figure 6 is anV enlarged fragmentary sectional :view of respectively, which cooperate withinwardly spacedinsulated walls 22 and 24, respectively,vfor defining an inner I refrigeration chamber 26 withthe lower insulated wall portion 28. A suitable cover member 30 insulated as at 32 and having a downwardly extending central portion 34. y

2,883,835 Patented Apr. 28, 1959 ice fitting within the refrigeration chamber `26 .is provided,1it being noted that end portions 36 and 38 cover the tops of the .compartments 14 and 16, respectively.

A pair of combined compressor and expansion chamber assemblies 40 and 42 are suitably mounted inthe com'- partments 14 and 16, respectively, andare in communi. cation 'with a referigerationcoil 44 of any suitable char-l acter for cooling the refrigeration chamber 26.

The combined expansion chambery and compressors 40 and 42 each include a cylinder housing 46 having a plurality of exterior heat dissipating annular baffles 48 which are operable to conduct heat from the interiorlof -the cylinder body 46 through the contact with air communieating in the chambers 14 and 16 through a louvredpor- Y tion 50 in the side walls- 18 and 20 Vof the refrigerator. The cylinders 46 each include therein a suitable .free floating piston or pressure responsive movable wallfelement. l

52 having conventional peripheral seals providingv two*- separate variable volume chambers 54 and 56, when the pressure responsive movable wall 52 reciprocates on a suitable guide rod 58 suitably supported .in the cylinder'- 46 by means of a transverse brace element 60.vfor ex. ample.

The lower chamber 54 of the cylinder 46 has a suitable apertured bottom wall portion 62 communicating with a metering valve 64 of any suitable character which includes a lower threaded nipple portion 66 connectible by means l of a .suitable nut 68 to a source of compression fluid such as carbon dioxide, nitrogen, etc., contained inther tankv 70, said tank including a conventional control valve 72;

Although not shown, it is to be understood that the .ende f compartments 14 and 16 will include suitable access porf tions bywhich the tank 70 may be replaced.V once'the pressure therein has been dissipated.

Theupper portion of the cylinder46 incorporatesthere-f on a metering and pressure control valve. assembly indiey cated generally at 74 which is suitably connected to a re-Y frigeration coil 44, and thus when the pressure reespon- Y sive movable walls 52 of the assemblies 40'` and -42v are in I the position shown in Fig. l, pressure exerted inthe variable volume chamber 54 to 'which the tank 70 is-in com-1M munication with by means of the metering valve 64, causesA pressure to be exerted on the chamber-S6 thereabove. The chambers 56 and the refrigeration coil containing Aa suitable readilycompressible refrigerant of any suitable character, and when the aforementional compression .takes place, if movement of the refrigerant through the valve assemblyL 74 is prevented, the refrigerant willfbecomf-- pressed Within the chamber 56 and become heated.up, the heat being dissipated kby the annular fins 48 aspreviously mentioned. A refrigerant will then assume a liquid form after cooling olf, and will be ready for distribution in therefrigeration system, :passage through. the refrigeration coil for cooling and picking up the heat contained in they refrigeration chamber V26, after which said refrigerant passes through a valve .assembly 74 inthe other.' com-vv partment and the other variable volume chamber 56Y will perform as an expansionA chamber. When the charnf` ber 56 functions as an expansion chamber, pressure I.'-is

exerted on the adjacent chamber 54 and -movement therefr through of anyvair contained therein is restricted by con;= trol of the valve 64, thus preventing an-excessive move-J ment of a refrigerant through the system.

As most clearly seen in Figs. 2 and 3 the-cy1inderr46 includes an upper threaded end portion 76 threadedly re-Y.-

ceiving a support cap element 78 comprising the base .or

support for the Vmetering and pressure controlyalve'- asf-f sembly 74. 'Ihe cap member 78 includes a suitably aperf tured portion 80 surrounded by a suitable seal 82 and re..- ceiving therein a valve body member 84 which includes aw projecting portion 86 received in said-aperturef80w They-Ta portion 86 of the valve body 84 includesfa:vertically-disfare aessse posed bore portion 88 communicating with an internal transverse or horizontally disposed cylindrical bore 90, said bore portion 88 terminating exteriorly in a conical valve seat 92. A temperature responsive bimetallic elongated control element 94 comprised of the dissimilar metals 96 and 98 is secured by means of a suitable rivet 100, for example, within the variable volume chamber 56, the distal end of the portion 96 including a conical valve element 102 engageable within the conical valve seat 92 of the valve body 84. The valve element 102 will be seated on the valve seat 92 and the temperature in the chamber 56 is raised due to the compression caused by the pressure responsive movable Wall 52, and until the heat of compression of the refrigerant contained in the chamber 56 is dissipated by the baiiies or iins 48 communication between the bore 88 and the interior of the valve body will be prohibited.

The valve body 84 includes a bore portion 104 substantially parallel to the bore 88, said bore portion 104 cornmunicating with the interior bore 90 of the valve body terminating in conical valve seat 106 receiving therein a ball check element 108 `spring urged by means of a compression spring 110 into sealing and seating engagement in the valve seat 106, the spring being supported in a nipple element 112 in a central bore portion 114 thereof, said nipple element being exteriorly threaded at 116 and being secured in a suitably threaded aperture portion 118 defining a continuation of the valve seat 106, said nipple element 112 including a transverse lateral bore portion 120 communicating with the bore portion 114 in which the spring 110 is supported. Thus, communication between the interior of the variable volume chamber 56 to the bore 90 of the valve body 84 will be permitted when the compressive pressure of the spring 110 on the ball check 108 is overcome.

It will be noted in Fig. 3 that the valve body 84 includes a pair of outwardly extending flanges 122 and 124 which are suitably apertured to receive suitable fastening screws 126 for securing the valve body 84 to the cap member 78.

The valve body 84 includes an upper vertically extending projection 128 having a vertical bore portion 130 extending therethrough and communicating with the internal bore 90, the bore 130 being intersected by a transverse bore portion 132 rotatably supporting a rotatable shaft 134 having a transverse bore portion 136 for communieating with the bore 130 and permitting communication between opposite sides thereof, the shaft 134 terminating in a shoulder portion 138 engageable on one side of a projecting portion 138 and terminating in a transverse manually engageable handle 140, the other end of the shaft 134 including a circumposed lwasher element 142 and an enlarged end portion 144 for retaining said shaft in the bore portion 132. The projection 128 is threaded at 146 at its upper end for receiving a connecting element 148 for securing thereon one end of a purge line 150, the line 150 and the apertured shaft 134 being utilized to neutralize the pressure between the compressors 40 and 42 when the compressing tank 70 is being switched from one side to the other, or when the refrigeration system is being started.

The valve body 84 includes at one end a projecting nozzle portion 154 externally threaded at the end 156 for receiving a suitable connecting element 158 for connecting the refrigeration coil 44 thereto, the projection 154 including a centrally bored portion 160 in coaxial alignment with the bore portion 90 of the Valve body member, and said projection portion 154 includes a transverse bore portion 162 receiving the rotatable shaft 164 of a valve element having a transverse aperture portion 166 alignable with the bore portion 160 for permitting communication between the refrigeration coil 44 and the interior of the valve body, said shaft 164 including an adjusting handle element 168 and being secured to the projection 154 by means of an enlarged end portion 170 in circumposed washer element 172.

The bore portion 160 terminates interiorly in an annular conical valve seat portion 174, said valve seat and movement of refrigerant through the bore portion 160 being controlled by a valve element 176 carried on an elongated arm 178 reciprocably supported in the housing bore portion 90 by means of a pressure responsive movable wall 180, said rod 178 extending through the pressure responsive movable wall 180 and including iixedly secured washer elements 182 and 184 secured on opposite sides thereof. Pressure responsive movable wall element 180 is engaged by one end of a compression spring element 186 circumposed on the rod element 178, the other end of the spring being engaged with a suitable abutment washer element 188 reciprocably carried on the rod 178, tension on the spring 186 being adjusted by means of a suitable adjusting screw 190 exteriorly threaded at 192 and supported in a suitable cap element 194 threadedly secured at 196 in the opposite end of the housing member 84. The screw element 190 includes an internal bore portion 198 reciprocably receiving the end 200 of the rod 178.

Thus, after the valve element 102 in the temperature responsive bimetallic element 94 moves away from its valve seat 90, compressed refrigerant wil1 enter the chamber 202 formed on one side of pressure responsive movable wall 180, and after the pressure therein is great enough to overcome the spring pressure 186 which has been adjusted by the screw 190, the pressure responsive movable wall 180 will move to the left toward the chamber 204 formed thereby, and with such movementy the rod 178 and the valve element 176 thereon will move away from the valve seat 174 permitting the movement of the referigerant into the coil 44.

Provided in the body portion 84 in the extension 154 thereof is an internal passage portion 206 which communicates with the passage portion or bore portion 160 thereof outwardly of the valve shaft 164, said bore portion terminating in an internal abutment portion 208, see Fig. 3, in the valve body 84 and including a horizontally disposed valve seat 210. The valve body 84 includes a vertically disposed internally threaded boss portion 212 threadedly receiving an adjusting screw 214 having a central bore 216 reciprocably receiving a rod element 218 which includes conical valve element 220 engageable in the valve seat 210, said rod element 218 including ixedly secured annular abutment washer element 222 engageable with a compression spring 224 which engages the inner lower end portion 226 of the adjusting screw 214.

When one of the compressors functions as an expansion chamber, the refrigerant will be urged through the passage 206 fulcruming the spring pressure 224 on the valve element 220 and then pass into the chamber 202, land inasmuch as the spring pressure 186 is greater than that of the spring 110 on the ball check 108, the refrigerant will pass through the bore 104 into the variable volume chamber 56 of that compressor which is acting as an expansion chamber. Additionally, the passage 206 may serve as a bypass for the chamber acting as the refrigerant compressor, when the compressor acting as the expansion chamber has its adjusting screw 214 so adjusted as to prevent the rapid movement of the refrigerant in the system, thus the refrigerant would circulate through the passage 206 past the valve seat 174 and through the bore ff 160 forming a complete cycle within the metering and pressure control valve assembly per se.

As will be seen in Fig. 1, the tank 70 including the compression gas is used with compressor assembly 42, and after the pressure responsive movable wall 52 has been urged upwardly to a position approximating the dotted line position shown relative to the assembly 40 in Fig. 1, the tank 70 may be moved to the compartment 14 and the refrigeration cycle will be reversed in a readily apparent manner thus affording a readily available and highly expeditious portable refrigeration cycle usable for picnics, and the like, orusable in larger installations if desirable. l

It will be noted `from the arrangement of parts, noteA Fig. 2, that when a given charge of compressed refrigerant is permitted to pass through the bore 160, the presavailable from the tank 70 is suiicient, the pressure responsive movable wall 52 Lin the cylinder 56 will be caused to move up an increment of travel resulting in an increase of heat on the refrigerant and laccordingly operation of the temperature responsive bimetallic assembly 94 resulting in the cycle of vlcompression of the refrigerant, cooling oi of the sameand subsequent release of refrigerant into the coil 44 as previously described.

The embodiment of invention disclosed in Figs. 4 through y8 incorporates'in the dual cycle refrigeration system of Figs. l through 3, means for maintaining a constant temperature in the refrigeration compartment 26,-as lwell as means for providing an automatic reversal of function of Ithe pair of combined compressor and expansion chamber-units, whereby each automatically operates sequentially as a compressor or expansion chamber.

As seen in Fig. 4, like parts of Figs. l through y3 are identified by means of similar reference characters, Wherein the `combined compressor and expansion chamber assemblies are identiiicd at 40' and 42', suitably supported in the respective end compartments 14 and 16, each of the assemblies incorporating in a cylinder portion 46' a pressure responsive movable 'wall element 52 defining variable volume pressure chambers 54 'and 56', and include on a cap member 78 -a combined metering and pressure control valve assembly 74 of the identical char acter of that described relative to Figs. 1 through 3, said valve assembly 74 cooperating with and functioning with the refrigerator coil 44 in the identicalmanner previously described relative to the first embodiment of invention.

It will'be noted that the cylinder member 46 includes heat'vdissipating annular ns 48and when lpressure vis available in the variable volume chamber 54, as seen in Fig. 4'for example, the pressure responsive movable Wall 52 Will move upwardly toward the cover member 78', it being understood that if the pressure responsive movable wall`52 were to reach its uppermost positionvpossible in the cylinder member 46', no further refrigeration would take place-since the compressor end compartment 14 would'no longer be operating, and until the compressor compartment 16 begins to'operate as a compressor instead of an expansion chamber, lthe refrigeration system will not be operating.

Additionally, it is desirable that the refrigeration cycle is not in constant operation but rather that the temperaturein the refrigeration chamber 26 be maintained constant depending on what temperature is desired, and accordingly,"a temperature control valve assembly 230 is suitably lmountedyvithinv the refrigeration chamber 26, and/is operatively connectedto a cutout valve assembly 232'suitablymounted in the compartments 14 and 16 and operatively connected between the compression tank and thel cylinder members 46 so that when the temperature in the refrigeration compartment-26 exceeds a predetermined temperature, the valve assembly 230 will function to control compression iiuid in the assemblies 40 or 42.

Although the temperature control valve assemblyf230 is disclosed in Figs. 4 through 8 as being used with the embodiment of invention having an automatic reversing of the dual cycle refrigeration system, it is readily apparent that the temperature control may be utilized with the embodiment ofinventio'n disclosed infFigs. l through 3,

6 s and the disclosure of the temperature control valve assembly with the embodiment of invention of Figs. 4 through 8 being merely by way of example.

As seen in Figs. 4, 6 and 7, the temperature control valve assembly 230 includes abimetallic temperature responsive element 234 suitably mounted at 236 within the refrigeration compartment 26, the lowerend of the bimetallic element 234 being suitably 'connected to one end of a linkage element 238 lwhich is pivotally connected at its opposite end to a pivot element 240 which connects said link element 238 at a distal end of a piston rod 242 connected integrally toav piston 244having a suitable annular seal portion 246, said piston 244 being reciprocably received within a iluid motor cylinder bore portion A248 in a lfluid motor cylinder 250 which is suitably supchambers 256 Iand* 25.8 'within the bore portion 248, the

chamber 258 containing therein force transmitting hydraulic fluid 260, the chamber Abeing formed by a centrally bored plug element 262 sealingly receiving one leg of a T-pipe fitting 264 which has fluid conduits 266 and 268 extending -from'the opposite legs, each of said conduits being operativelyxconnected to'a remote controlled motor cylinder 270 of the cutoff valve lassembly 232.

As seen in Fig. 6, the temperature Acontrol valve is intended to illustrate the 'piston 244 in the position obtained when Athe temperature inthe refrigeration charnber 26 is above or higher than'the desired predetermined temperature, and accordingly, when a temperature is reached which is below or-rlower thanlthe predetermined tempera-ture, the temperatureresponsive bimetallic element 234 Ywill movetoward the right asindicated by the direction arrow whereuponpressurey will be exerted on the fluid 260 resulting inlurging pressure through the fluid conduits 266 and 276,8 to the vservo motor cylinders 27). The ycylinder 270 includes a motor bore portion 272 reciprocably supportingA the piston 274 therein, said piston having an annular seal 276 forming with a centrally apertured end wall memberl 27,8 in variable volume chamber 280, and formingwith a suitable transverse supportplug element 282 in a second variable volume chamv'ber 284. The variable volume chamber 280 is iilled with iiuid 260 and thuspressure exerted Vby the piston 244 will exert a similarpressureron the piston 276 moving the same toward the left as-seen in Fig. 7, wherein leftward movement or suction by the piston 244 results in a similar .suction in the pistonn274in J the remote motor resulting in rightward movementof said piston.

The piston 274 has secureduther'eto a piston rod element 286 extending throughNthe-plug element 282 and `which has threadedlyzconnected at 238 in any suitable manner to a valve rod 290 reciprocably supported in a suitable wheeling bushing 292lsecured in a partition wall 294 of the cylinder 270, said valve rod 290 including on the end thereof a valve seal 4element 296 Which is received within the compressionuid -chamber 298 formed in the cylinder 270 by means of a centrally apertured plug element 300 securedinkthenend of the cylinder 270. The plug element 300 asmentionedis centrally apertured at 302 andincludes an in ner valve seat portion 304 engageable with the valvefseal element 296, said central aperture portion 302 communicating With a suitably secured pressure iiuid lconduit 306 which communicates with a conventional metering valve 64 ofa character similar to that used in the embodiment of Figs.y l through 3, chamber 298 also communicating with a bore portion 308 to a uid conduit l310 communicating with a compression rfluid supply "tank 70'.

A second supply tank 70" may be provided in cornmunication with the cutoff valve assembly 170, see Fig. 4,

*and if desired (althoughnot'shown) the singley supply tank of compression uid may be utilized in the refrigerator.

The cylinder 270 may incorporate thereon an integral ange 312 and accordingly be secured on an adjacent support wall of the refrigerator by means of suitable fastening elements 314. The valve rod 290 has xedly secured on an intermediate portion thereof an annular collar element 316 which has pivotally secured thereto a pair of diametrically opposed U-shaped support bracket elements 318 and 320 which have their leg portions overlapping and pivotally secured together by means of a transverse pivot pin element 322 extending through the rod 290 and the legs of the aforementioned bracket elements, said bracket elements having extending laterally from their web portions spring support rods 324 and 326, respectively, the ends of which being reciprocably received within suitable apertured diametrically opposed tubular pivot elements 328 and 330, respectively, suitably supported in respectively parallel relationship on opposite sides of the rod 290, the rods 324 and 326 having circumposed thereon compression spring elements 332, see Fig. 8, which have opposite ends in abutting engagement with the U-shaped support elements thus providing an olf-center toggle arrangement which positively urges the valve element 296 into sealing engagement with the valve seat 304 by virtue of movement of the piston 274 so that compression uid may travel from the fluid conduit 310 to the conduit 306 for permitting the compression step of the refrigeration system to function, or to positively urge a sealing relationship between the elements 296 and 304 for cutting olf the passage of compression fluid through the conduit 310.

The portion of the cylinder 270 dened by the partition 294 and element 282 is open in order to permit the ready maintenance and assembly of the remote motor device.

The automatic switch-over control valve is indicated generally at 334 and includes a cylinder portion 336 having a suitable integral connecting ange 338 for accommodating suitable fastening elements 340 for securement in the refrigerator, said cylinder incorporating an internal lower portion 342 reciprocably supporting a piston element 344 having a suitable annular seal 346, the piston 344 including an integral piston rod 348 extending through a suitable partition plug element 350 in the cylinder 336, said rod 348 including a pair of transverse longitudinally spaced bore portions 352 and 354, said bore portions being contained in a portion 356 of the piston rod 348 which extends outside of the cylinder 336. The portion 356 of the piston rod is reciprocably and sealingly supported in a surrounding bracket element 358 which includes a pair of spaced bifurcated leg portions 360 secured on diametrically opposite sides of the cylinder body 336, said portion 358 including a pair of longitudinally spaced bore portions 362 and 364. The portion 358 has secured at its distal end 366 in any suitable manner a pair of outwardly outstanding legs 368 and 370 rotatably supporting diametrically apertured tubular elements 372 which reciprocably receive in the diametrically apertured portion thereof rod elements 374 which are pivotally connected at their inner ends to a suitable pivot element 376 on the distal end 378 of the piston rod portion 356. Suitable compression spring elements 380 are circumposed on the rod elements 374 between the element 372 and the -pivot portion 376 providing an o-center toggle similar to that described relative to Fig. 7, for the purpose of positively aligning apertures 352 and 354 of the piston rod portion 356 with either the aperture portion 362 or 364, respectively, in the portion 358.

The aperture portions 362 and 364 are respectively suitably connected at one side to fluid conduits 382 and 384 which communicate with the control valve 64' and which respectively permit the ow of compressing fluid toward or away from the supply tanks 70 or 70". It

is to be understood that when flow is permitted through the conduit 382' in the compartment 14 which accordingly results in urging the pressure responsive movable wall 52 upwardly for compressing the refrigerant in the variable volume chamber 56', the conduit 384 will be closed. Additionally, considering compartment 16, a -comparable conduit 382 will be closed as seen in Fig. 5, and the conduit 384 will 4communicate with the variable volume chamber 54 by virtue of the association of the portions 354 and 364, and whatever compressing fluid is used in the variable volume chamber 54 will be urged back through control valve 64 and may be released into compartment 14 or 16 for aiding in cooling assemblies 40 and 42. It will be noted that the bore portions 362 and 364, respectively, are connected to suitable fluid conduits 386 and 388 suitably connected to a bottom portion 390 of the cylinder members 46'.

The piston 344 in the cylinder 336 denes opposite variable volume chambers 392 and 394 filled with a suitable force transmitting uid of any suitable character, chamber 394 suitably communicating with a uid conduit 396. Thus it will be seen in Fig. 4, for example, the compartments 394 of each of the cylinders 336 are in direct communication with each other and accordingly movement toward the right of the piston 344 in the variable volume chamber 394 the switch-over assembly and compartment 16, for example, results in leftward movement of the piston 344 of the similar variable volume chamber 394 of the switch-over 'assembly and refrigerator compartment 14.

The switch-over valve assemblies are actuated by the pressure responsive movable walls 52 reaching an uppermost position in the cylinders 46. The cap members 78 each include an integral cylinder chamber of a fluid motor 398, said uid motor including a cylinder 400 suitably secured in vertically extending relationship at one end to the cap member 78', the other end of which being suitably apertured at 402 being in communication with a uid conduit 404 connected to a suitable T-tting 406 which has one leg in communication with a variable volume iluid chamber 392 in the switch-over control valve cylinder 336, the other leg being in communication with a uid conduit 408, thus the variable volume uid chambers 392 of the switch-over valve control assemblies 334 in each of the compartments 14 and 16 are in communication with each other and the previously mentioned piston elements 344 will be reciprocated in opposite directions for the purpose previously mentioned, by actuating structure to be subsequently described.

The cylinders 400 have an internal bore portion 410 reciprocably receiving a suitably sealed piston element 412, said piston element including an integral piston or actuating rod 414 reciprocably received in a suitable support bushing 416 threadedly secured in the cap member 78', said rod 414 including a distal end portion 418 depending into the variable volume chamber 56' for engagement by the pressure responsive movable wall 52' when the same is reached at the upper end of the cylinder 46' whereby pressure exerted on the actuating rod 418 results in upward movement of the piston 412 applying pressure on a force transmitting uid 420 contained in the variable volume chamber 422 formed in the cylinder 400 by the piston 412, the fluid 420 lling conduits 404 and 408 as Well as the variable volume chamber 392 of the cylinder 336 of the switch-over control valve, and thus when either of the pressure responsive movable walls 52 approach the uppermost limits of the cylinder 46', it being understood that the assemblies 40 and 42 alternately provide compressors and expansion chambers of a dual cycle reversible refrigeration system, said pressure responsive movable walls 52 will result in actuation of the switch-over control valve assemblies 334.

Thus there has been disclosed a dual cycle reversible refrigeration system which readily conforms with the objects of invention heretofore set forth, incorporating the features of a pair of combined compressor and expansion chamber assemblies in conjunction with a refrigeration coil, the reversal of a refrigeration cycle may be accomplished by applying a pressure source of compression uid to oppositely disposed combined compressor and expansion chamber assemblies, and there has further been disclosed features permitting automatic control for a predetermined temperature in a refrigeration compartment as well as an automatic switch-over assembly for automatically reversing the dual refrigeration cycles.

Numerous position and directional terms, such as top, bottom, side, etc. are utilized here and have only a relative connotation to aid in describing the device and are not intended to require any particular orientation with respect to any external elements.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed as new is as follows:

1. A dual cycle closed non-circulating reversible refrigeration system for a wholly portable refrigerator, said system comprising a refrigeration coil, a pair of refrigerant compressors, each compressor including a cylindrical member, a pressure responsive movable wall separating said cylindrical member into an adjacent pair of variable volume chambers in said cylindrical member, means connecting each refrigerant compressor to one end of the refrigeration coil for causing ow of refrigerant therethrough, means for controlling and causing alternate operation of the compressors to provide reversing flow of refrigerant through said coil between said compressors, a first of said chambers operatively connected to said means controlling and causing alternate operation of the compressors, a second and a third of said chambers connected to opposite ends of said refrigeration coil, and means communicating between said compressors for neutralizing the pressure differential of refrigerant between said compressors and refrigeration coil.

2. A dual cycle closed non-circulating reversible refrigeration system of claim 1 wherein said cylinder members each include heat dissipating means for removing heat from the refrigerant and condensing the same.

3. A dual cycle closed non-circulating reversible refrigeration system of claim 1 wherein said cylinder members each include heat dissipating means for removing heat from the refrigerant and condensing the same, the means controlling and causing alternate operation of the compressors comprising valve means in communication with one of said variable volume chambers of the cylinder members, and a source of gas under pressure alternately communicable between each of the one of said variable volume chambers.

4. A dual cycle closed nou-circulating reversible refrigerating system of claim 1 wherein said cylinder members each include heat dissipating means for removing heat from the refrigerant and condensing the same, the means controlling and causing alternate operation of the compressors comprising valve means in communication with one of said variable volume chambers of the cylinder members, and a source of gas under pressure alternately communicable between each of the one of said variable volume chambers including temperature responsive control means operatively associated between the source of fluid pressure and one of the variable volume chambers for inhibiting said fluid pressure and maintaining a predetermined temperature in the refrigerating coil.

5. A dual cycle closed non-circulating reversible refrigeration system of claim l wherein said cylinder members each include heat dissipating means for removing heat from the refrigerant and condensing the same, the means controlling and causing alternate operation of the compressors comprising valve means in communication with one of said variable volume chambers of the cylinder members, a container of gas under pressure alternately communicable between each of the one of said variable volume chambers including temperature responsive con trol means operatively associated between the source of uid pressure and one of the variable volume chambers for inhibiting said uid pressure and maintaining a predetermined temperature in the refrigerating coil wherein said temperature responsive control means comprise a thermally actuated iluid motor, and a fluid operated slave motor control valve operatively connected to said source of fluid pressure.

6. A dual cycle closed non-circulating reversible system of claim 1 wherein there are automatically operated switch means contained in said cylinder member and engageable by said pressure responsive movable walls for reversing the refrigerating cycles between said compressors.

7. A dual cycle closed non-circulating reversible closed refrigerating system of claim l wherein there are alternatingly operable uid pressure source control means in communication with said container of compressed gas, an automatically operated switch means contained in said cylinder member and engageable by said pressure responsive movable walls for reversing the refrigerating cycles between said compressors, said automatically operated switch means comprising a fluid motor including a reciprocable piston rod element movable by said pressure responsive movable walls, and slave motor operated valve means operatively connected to the uid pressure source 'for reversing ow of refrigerant in said coil.

References Cited in the file of this patent UNITED STATES PATENTS 1,508,833 Weber et al Sept. 16, 1924 2,256,139 Craig Sept. 16, 1941 2,638,123 Vargo May 12, 1953 2,723,537 Clark Nov. 15, 1955 2,772,543 Berry Dec. 4, 1956 

